everything everywhere

alpha waves 

10 hz

alpha= routing mechanism, shutting down regions actively that are not needed 

By attending to something, alpha has an increase on the other side, because it's inhibited, you don't pay attention to that region, and alpha goes down on the attended side 

artifact

muscle, movement, or bones that block the eeg signal 

intracranial eeg

places electrodes directly into the brain

more localised signal in real time

demyelination

e.g multiple sclerosis

no swan cells or myelin sheaths for the axon 

Issue; conductivity, communication of the neuron breaks down 

Results in vision loss, communication issues, etc

parameters of a wave

• amplitude/ power

• frequency

• speed

• height

beta waves

13-30 hz

theta waves

4-8 hz

most commonly associated with motor cortex, but also with concentration, executive functioning, frontal cortex jobs 

• Specific fingerprint of highly concentrated top down thinking 

delta

0.5-4 hz

slow wave sleep 

spontaneous synchrony

slow oscillation= synchrony 

Oscillation is when they fire in a rhythmic pattern 

alpha oscillations prevent firing in a phasic manner

• ‘pulsed inhibition’  

Rhythmic pattern that has cumulative input onto the intake neuron and post synaptic neurons, so they get enough energy to create an action potential and fire, then pass it along to the next one 

TIME-FREQUENCY PLOTS.

• the x axis is time

• the y axis is the frequency

• the increase and/or decrease is shown in the colour temperature (blue vs red)

cognitive control 

overriding something well learned, replacing it with something more novel 

includes:

1. creating an action plan 

2. overriding learned behaviours

3. maintaining & mentally manipulating info 

4. monitoring our behaviour and correcting it when necessary 

5. managing multiple tasks 

overriding learned behaviours

• flanker task

• when people are correct and don’t make mistakes, more activation in the inferior portions of the frontal cortex

• mainly right lateralised areas

• stroop task

• brocas area; exert control over articulatory motor planning

• lateral prefrontal cortex; important for modulating behaviour when you have to override a well learned behaviour

• left lateralised

managing multiple tasks

• multiple errands test 

• tendency for inefficiency 

• anterior damage; can make the plan but can’t action it. inability to flexibly manage multiple goals 

creating an action plan 

• hotel task

• very high level of task switching

• involves some prospective memory; remembering to switch tasks without external cues

• internal task switching whilst keeping bigger picture in mind

• damage to anterior regions perform poorly here

prospective memory

• the ability to keep in mind that you have to do something at a future time, often linked to a time or place

• used to indicate when a switch is required from internal cues usually

monitoring behaviour

• wisconsin card sorting task

• analogical reasoning element 

• listening to feedback to guide your next decision 

• repeating behaviours when it is no longer advantageous to do so commonly seen in people with damage to lateral pfc 

rule violations

• damage to right lateral pfc 

• gray matter thinned in these areas 

• right hemisphere, and right lateral pfc implicated in tasks that involve listening to feedback or changing the course of your actions based on outside information 

a simple theory (cognitive control)

• lateral pfc structures maintain an internal goal state → if its not active it can no longer control your activity 

• bias activation away from habitual routines in favour of the goal 

  

anterior pfc regions

• task switching 

left inferior pfc regions

• control of verbal processing

right inferior pfc regions

• control in nonverbal regions 

koechlin & summerfield model

• green; premotor cortex & sensory control = well learned response 

• blue; posterior pfc & contextual control = modifying behaviour based on external cues 

• purple; anterior pfc & episodic control = using past instructions or recent information 

• pink: the frontal pole & branching control =  dynamic switching between multiple task sets 

hierarchical models

• all pfc regions work by modulation activity in more posterior areas 

• further up the hierarchy goes, the control becomes more abstract, less domain specific 

• frontal pole; controls the control systems, schematic control 

• lateral pfc: contextual control, domain specific. left = language, right = spatial, non verbal

• motor cortex: sensory-motor control, basic control

lateral pfc

• top down control of mental representations to meet internal goals 

• cold cognitive control 

• low stakes effortful situations 

the frontal pole

• explore vs exploit 

• value judgement multitasking 

• fmri study; signalling from frontal pole helps us decide when we want to disengage from exploiting, conservative behaviour, and explore 

• rostral pfc to make values based decisions 

spontaneous confabulations

• reporting things that aren’t true about the past and present 

• ventromedial pfc damage; precedes hippocampus, guides search in personal timeline 

• overabundance of reports of incorrect autobiographical memories 

dorsomedial pfc

• motivation and resource allocation 

ventromedial pfc

• control in high stakes situations

• goal oriented behaviour 

key structures in emotional processing

• hippocampus

• amygdala

emotion

• a rapid and transient response to a stimulus with value to a person

• consist of physiological changes, a behavioural response, and a subjective experience, intrinsically pleasant or unpleasant

mood

a more persistent state which shares some of the same subjective features of emotion 

affect

a broader term encompassing emotion + mood 

classifying emotions

• positive vs negative

• basic vs complex

• arousal level vs valence

ekman theory of classifying emotion

core emotions biologically pre programmed

= happiness, sadness, disgust anger, fear, surprise 

complex emotions draw on the same feelings, but combine them with social and cultural factors 

feldman-barrett theory of classifying emotion

you can put emotion on a continuum based on arousal and positivity / valence 

high arousal = anger, excitement, nercousness

low arousal = sadness, contentment

physiological component of emotion 

autonomic nervous system → sympathetic and parasympathetic systems 

sympathetic nervous system

• ‘fight or flight’

• up regulates respiration 

• dilates lungs, pupils, blood vessels 

• increases heart rate & perspiration 

• suppresses digestion 

parasympathetic nervous system

• ‘rest and digest’

• sleep rest & digestion

• conservation of energy 

measuring emotional responses

• skin conductance response (SCR): measures change in perspiration 

• heart rate / heart rate variability 

• self report tools e.g PANAS

→ best to use the tools together so you can get a fuller picture of everything 

PANAS

• positive and negative affect schedule

• looking at a person across a small period of time, usually a week 

the amygdala: fMRI evidence

spohrs 2018

if we show people expressive faces, they respond with activity in the amygdala 

→ not a great comparison between faces and shapes; lots of sites activated because faces are so different to shapes 

fear conditioning paradigm 

• circle matched with mild electric shock on fingers 

• classical conditioning 

• when viewing shapes alon

  

  e under the scanner after learning, the circle had significantly more activation in the amygdala compared to other shapes 

amygdala and memory

• kensinger 2011

• events eliciting higher amygdala activation in phase 1 were rated as more vivid in phase 2 

• BUT accuracy/details the same irrespective of amygdala activation 

•  indicates that emotional valence enhances ability to remember, but only a more robust subjective experience 

effects of damage on the amygdala

• may fail to show normal fear conditioning 

• may fail to show a memory benefit for emotionally significant events 

• often poor at identifying facial expressions 

SM

• bilateral damage from urbach-wiethe disease

• affected valence- missing negative emotions that perform a function e.g fear of snakes 

• overly positive & overly familiar 

amygdala & story recall

phineas gage

• left ventromedial prefrontal cortex damaged 

• impulsive, fearful, loss of control  

• behaviour changes around affect, inability to use good judgement for hot cognition 

clinical featires of vmPFC damage

• Emotional dysregulation, changes in emotional experience

philosophical calmness in high emotion situations 

• Diminished empathy, poor social awareness

Also true of damage to amygdala, but the problem here is somewhat higher up; can see it but cant interpret it 

• Poor decision-making, irresponsible behaviour, risk-taking

Specifically in hot context cases

vmPFC changes in emotional experience

• increased impulsivity 

• increased aggression (some people get this with impulsivity, not all)

→ general disinhibition

• diminished empathy / poor social awareness 

NPI

• neuropsychiatric inventory 

• designed to assess wether a person demonstrated increased impulsivity or reduced social awareness 

• head injury sample: significantly lower scores with right vmPFC damage 

diminished empathy

• tranel & damasio 1994

• healthy participants; emotional picture evokes scr

• damage; can describe picture in detail, but no scr

→ issue is making the perspective leap, understanding what the other person might be feeling

poor social awareness

• patients score poorer than controls on the faux pas task 

• addresses higher level empathy than amygdala damage = perspective AND empathise 

• theory of mind, but for social rules and consequences 

amygdala vs vmPFC

• amygdala: ‘signals’ emotional valence, particularly negative valence 

• vmPFC: emotional regulation, cognition that relies strongly on emotion 

poor decision making, irresponsibility, risk-taking

• gambling game 

• vmPFC patients can explain the rule, but don’t act on it 

• difference between ability to rule detect, and ability to respond positively within the hot context 

• SCR: controls develop an anticipatory scr before selecting from a bad deck. patients get scr after the bad card, but don’t develop an anticipatory scr 

• cannot use emotional response in a proactive way to shape future decisions 

• left pfc crucial for this task 

hot cognition

• thinking and decising how to act when the emotional stakes are high

• using emotional responses to guide decision making in complex high level decision making 

• gut instinct before verbal explanation 

= winning poker 

= trading on the stock market 

= deciding wether or not to have cake 

cold cognition 

• stroop task 

• thinking out a difficult mental problem 

• dividing a large goal into sub goals 

gambling fMRI

• people who did well on the iowa gambling task showed increasing activity in the left vmPFC as the trial progressed 

• right insula also activated= operate as a network 

somatic marker hypothesis

• vmPFC: binds memories and their emotional and physiological associations 

• creates an index of the way you’ve felt in similar situations in the past, which you can revoke in future to guide your actions 

• facilitates fast decision-making 

limitations: 

• does it consider empathy or social awareness 

• does it consider causal vs association with bodily sensations 

descartes error

• damasio: we are not thinking machines that feel, we are feeling machines that think 

• it is not enough for us to be rational, that would be weird. we do a lot of things based on feeling and gut instinct 

white matter fibres / tracts

• arcate fasciculus= key language tract

• white matter tracts helps us understand the anatomical interconnections between regions

• structural connectivity

• the roadways of the brain = cant have good communication without good ways to connect areas

diffusion tensor imaging (DTI) 

• tracks the direction of movement of water molecules

• systematic flow in one direction indicates a large white matter tract

DTI clinical applications

• identifying diseases that affect long axons e.g multiple sclerosis

• psychologically; if basic scans down show anything but there are cognitive problems

• diffuse axonal injury in head injury and concussion, twisting and tearing large white matter tracts 

• know a lot more from these methods about structural problems that underlie amnesia

corpus colosseum 

• people experiencing significant amnesia tend to have lower white matter fibre volume

• corpus colosseum damage itself is occurring, but also predictive of greater amnesia, along with many other areas

functional connectivity

• the crosstalk between interconnected regions during a particular activity

• traffic on the road

• degree of cross talk between regions varies depending on the task

• can measure the degree of synchrony between activity in different regions - how does the bold signal change over time to map connection and communication between areas 

dynamic networks

• Lots of large scale networks operate as inhibitors of each other, so the networks will ebb and flow as the brain moves between thought and focus 

default mode network

• ‘day dreaming’ network

• active at rest 

• active when focused on internal thoughts 

• deactivated when focus shifts to external stimuli 

• inner reflection exploring ideas / solutions

• super portion of the

  prefrontal cortex

• number of lateral structures, but lots of key ones on the medial surface

• temporoparietal cortex, hippocampus, ventromedial PFC, posterior cingulate cortex 

DMN activities

• retrieving memories for past experiences, reliving mentally (hippocampus) 

• making judgements about themselves relative to others (VMPFC, social cognition and judgments on others) 

• mind wandering 

mind wandering

• button press tasks 

• greater activation of the DMN when day dreaming 

• able to measure beyond activities that require an external focus 

frontoparietal control network

• activated when performing a demanding task

• highly externally focused cognitive control & effortful tasks 

• controlling behaviour to achieve a goal

• large portion of the lateral PFC 

• parietal lobe 

• interparietal sulcus 

  

the salience network 

• signals when something is aversive or emotionally salient

• can respond to a thought or emotion

• helps to initiate rapid switches between networks

• dorsal anterior cingulate= signals when we need to exert effort on a task

• anterior insula= evaluates emotional and bodily states

anterior PFC

• the hotel task & complex problem solving

• real life problems & multi tasking involve dynamic switching between modes 

• damage to the anterior PFC; people get fixed in one network and then cannot switch to the other one 

depression

• increased connectivity, synchronicity, and overall activation within the default mode network 

• more time being introspective, more time ruminating 

• unclear as to wether cause or effect 

creativity in healthy people

• high scorers: tightly synchronised activity in parts of the default mode and fronto parietal control networks 

• low scorers: primarily posterior cross talk 

• suggests that creative thought involves flexible interplay between; 

1. Default mode network (internal thoughts, reflection, imagining, remembering)

2. Frontoparietal control network (goal directed top-down control of cognition, evaluation of ideas, etc.)

clinical neuropsychology

Aims to understand and help treat people who are experiencing nervous psychological difficulties, as a result of some type of brain disorder 

steps

1. is there a neuropsychological disorder present

2. what is the impact of this neuropsychological disorder on cognition, emotion, and behaviour

3. what other factors could explain presenting difficulties

4. treatment = education, recommendations, rehabilitation

TBI neuropsychological manifestations 

• cognitive impairment 

• impaired alertness / arousal 

• slowed cognitive processing 

• attentional impairment 

• learning and memory impairment 

• executive functioning impairment 

• aphasia 

• social functioning impairment 

TBI and cognition

• pathophysiology = what happens 

• injury severity n the brain as a result of the injury

• mechanisms of the injury

mechanisms of injury

• direct impact 

external forces colliding with neck or head= tsunami 

• acceleration - declaration 

forces of body movement have been so strong that it moved your brain 

• blast injury 

• penetrating injury 

an external object has penetrated through the skulls and into the brain 

direct impact vs penetration

• penetrating can be debilitating if its penetrated into critical areas of the brain

• BUT

• can also be less severe than direct, because the injury is localised rather than generalised 

rating severity of TBI

1. duration of loss of consciousness 

2. glasgow coma scale (gcs) 

1. post traumatic amnesia 

glasgow coma scale

• rates verbal responses, eye opening behaviour, and motor responses 

• 3 to 15 point scale 

• how alert a person might be 

post traumatic amnesia

• anterograde memory loss for events occurring immediately follow the injury 

• retrograde for events immediately piror 

• assessment; remembering objects a day apart

severity classification

• if one classification trumps the others, you move into that category 

mild TBI

• concussion 

1. any period of LOC

2. any loss of memory for events immediately before or after the accident 

3. any alteration in mental state at the time of the accident 

4. focal neurological deficit which may or may not be transient 

pathophysiology - focal

• contusion (bruise) 

more for direct impact 

• contrecoup contusions 

• intracranial bleeding 

contrecoup contusions

• onion in liquid in a jar

• brain hits the back and front of the skull 

intracranial bleeding

• if forces in the brain are significant enough to rupture a blood vessel

areas vulnerable to contusion

• prefrontal cortex 

results in issues with cognitive control, executive functioning, emotional control

• anterior and inferior temporal lobe 

located in the cavities 

results in difficulties with memory 

• less common;

• cerebellum

• superior parietal region 

pathophysiology; diffuse

• diffuse axonal injury 

• shearing of neural axons 

• tearing of bridging veins resulting in intracranial bleeding throughout brain  

• white matter has lower density, so more likely to be impact by forces from an injury 

• happens at a very micro level 

• more common injury than focal injuries 

• impacts more areas and bigger functions like memory due to them using a large number of regions 

cognitive recovery

• typically experience transient cognitive, emotional, and physical

• recovery often within 1-3 months post-injury and expected to have favourable long-term outcomes 

• prolonged or atypical recovery associated with acute injury conditions (LOC), severity of initial symptoms, preexisting or comorbid psychiatric, medical, or psychosocial factors 

moderate and severe TBI

• chronic impairments that limit ability to return to previous levels of functioning

• cognitive functioning typically improve over time with the most recovery seen in the first 6 months 

• improvements in basic cognitive skills (attention, orientation) precede improvement in more complex cognitive skills 

• recovery usually plateous at 18-24 months 

recovery

stroke (CVA)

• defined as a sudden onset of impairment in neruological functioning due to severe decrease of blood supply to the brain

• blood ocntains oxygen and important nutrients for proper functioning. if brain cells do not get enough of this, they die (infarct)

ischemic stroke

• starved

• most common in adults

• neuronal damage or infarct caused by inadequate blood supply to a particular part of the brain due to an obstruction 

• anterior circulation most frequently affected, 80% of cases

types of ischemic strokes

• embolic= a blood clot forms elsewhere in the body, breaks loose, and travels to the brain via the blood stream 

• thrombotic= a blood clot develops in the blood vessel inside the brain 

• vasospasm= the narrowing of intracranial arteries, which can lead to hypo perfusion (reduction in the amount of blood flow) 

the tree

• dimensions of blood vessels reduce as they circulate through the brain 

• smaller blood vessels are more vulnerable to blockages, but will impact less of the brain 

• if the blockage is in the trunk, it will effect the whole tree 

haemorrhage stroke

• less common → 12% of all strokes

• caused by a weakened vessel that ruptures and bleeds into the surrounding brain 

• associated with higher mortality

intracerebral haemorrhage

• bleeding within the brain tissue itself 

subarachnoid haemorrhage

• bleeding within the subarachnoid space

• spaces where the cerebrospinal fluid is has a rich blood supply

• if theres a rupture here it causes a change in pressure due to extra fluid, which compresses brain tissues

• mortality of 50% in the first 6 months after stroke